1. Field of the Invention
The present invention relates generally to telecommunications systems and methods for automatically ringing a subscribers telephone once the subscriber's line becomes idle, and specifically to allowing an attendant to implement a recall feature for a third party when that party's line is busy.
2. Background and Objects of the Present Invention
Since the beginning of the telephone in the 1870's, signaling has been an integral part of telephone communications. Such signaling typically includes the call setup, such as ringing the called party, and tear-down procedures. In modern telecommunications networks, signaling constitutes the distinct control infrastructure that enables provision of all other services. It can be defined as the system that enables stored program control exchanges, network databases, and other "intelligent" nodes of the network to exchange: (a) messages related to call setup, supervision, and tear-down; (b) information needed for distributed applications processing (interprocess query/response); and (c) network management information.
In addition, the Intelligent Network (IN) and the new Advanced Intelligent Network (AIN) have made possible the transfer of all types of information through the telephone network without special circuits or long installation cycles. In the IN, everything is controlled or configured by workstations with user-friendly software. Telephone service representatives can, therefore, create new services and tailor a subscriber's service from a terminal while talking with the customer. These changes are immediately and inexpensively implemented in the switches, rather than by the more traditional method: expensive programming changes made by certified technicians.
The IN consists of a series of intelligent nodes, each capable of processing at various levels, and each capable of communicating with one another over data links. Currently, the IN relies on the Signaling System #7 (SS7) network, which provides the basic infrastructure needed for the various signaling points in the IN. SS7, in turn, relies on Common Channel Signaling, which uses a digital facility, but places the signaling information in a time slot or channel separate from the voice and data to which it is related. This allows signaling information to be consolidated and sent through its own network apart from the voice network.
The various signaling points in the IN both perform message discrimination (read the address and determine if the message is for that node), and route messages to other signaling points. The basic three types of signaling points are: (1) Service Switching Points (SSPs); (2) Signal Transfer Points (STPs); and (3) Service Control Points (SCPs), each of which are described in more detail hereinafter.
With reference now to FIG. 1 of the drawings, the many Service Switching Points (SSPs) 100 serve as the local exchanges in a telephone network 90, a portion of which is shown in FIG. 1. The SSPs 100 preferably provide an Integrated Services Digital Network (ISDN) interface for the Signal Transfer Points (STPs) 110, as is understood in the art. The signaling information is handed off to the SS7 network and transferred to an end office (another SSP) using SS7 ISDN User Part (ISUP) protocol, which is responsible for all call setup and tear down.
The STP 110 serves as a router, and switches messages received from a particular SSP 100 through the network 90 to their appropriate destinations (another SSP 100). As is also understood in the art, the STP 110 receives messages in packet form from the SSPs 100. These packets are either related to call connections or database queries. If the packet is a request to connect a call, the message must be forwarded to a destination end office (another SSP 100), where the call will be terminated.
If, however, the message is a database query seeking additional information, the destination will be a database. Database access is provided through the Service Control Point (SCP) 120, which does not store the information, but acts as an interface to a computer that houses the requested information, as is understood in the art.
Currently, many large companies utilize a private branch exchange (PBX) to handle the switching for all calls to and from telephone extensions within the company. With PBX systems, proprietary phones can offer a multitude of high-tech features that greatly enhance the systems capability, such as call forwarding, conference calling, speed dialing, linked voicemail, which allows users to reach their voicemail from any phone at any company location without dialing into the system from an outside line, and station detailed message recording (SMDR), which provides the calling records of every extension in the system. ISDN protocols can be used within a PBX system to provide end-to-end digital communications for both voice and data, eliminating the need for costly dedicated lines for data communications, facsimile and video conferencing.
Typically, as indicated in FIG. 2 of the drawings, when a calling party 200 wishes to contact a subscriber 250 within a PBX system 220, but does not know the direct number for that subscriber, the calling party can dial a number associated with the main switchboard operator 240 or a number associated with an assistant to the desired subscriber 250, which can then be answered by an attendant 240. Attendants 240 have the ability to transfer incoming calls or even "park" calls towards a third party 250 (the desired subscriber). Therefore, if the calling party 200 calls Company X 230 and requests to talk to subscriber Y 250, the attendant 240 can transfer the calling party 200 to subscriber Y's extension 250.
However, if subscriber Y 250 is on the phone (the line is busy), the attendant 240 can pick up the line and offer a variety of choices to the calling party 200. For example, the attendant 240 can take a message, transfer the calling party 200 to subscriber Y's voicemail (not shown), or "park" or "camp" the calling party 200 towards subscriber Y 250. If, however, the calling party 200 wishes to have subscriber Y 250 return the phone call as soon as subscriber Y's 250 line is idle, existing technology only allows the attendant 240 to either monitor subscriber Y's 250 line continuously and once the line becomes idle, inform subscriber Y 250 that the calling party 200 would like to have the call returned, which is cumbersome for the attendant 240, or to "park" or "camp" the phone call against subscriber Y 250, which requires the calling party 200 to wait on the phone listening to elevator music or a ringing tone.
If, however, the calling party 200 dials subscriber Y 250 directly, the calling party 200 presently has the ability to enter a service code, e.g., *99, which initiates an automatic recall feature 210 within the calling party's switch (SSP) 215. The calling party's switch 215 then instructs the called subscriber's switch (PBX) 220 to monitor subscriber Y's 250 line for a predetermined amount of time, e.g., thirty minutes, and when subscriber Y's 250 line becomes idle, the called subscriber's switch 220 initiates a call between subscriber Y 250 and the original calling party 200. The calling party's 200 phone then rings with a special tone to indicate that the recall feature 210 has been activated. When the calling party 200 "answers" the call, the calling party 200 will hear typical ringing until subscriber Y 250 answers the call. However, when the calling party 200 has dialed an attendant, there is currently no method for implementing an automatic recall feature 210 for the desired called subscriber Y 250.
It is, therefore, an object of the present invention to allow an attendant to initiate an automatic recall feature for a third party when the third party's line is busy.